Telephone networks are used to connect a customer with a voice response unit associated with a commercial establishment such as a department store. In operation, a calling customer is connected through a telephone network to a voice response unit associated with the department store. The voice response unit responds to a calling customer connection by transmitting a voice prompt message over the telephone network to the calling customer. A typical voice prompt message instructs the calling customer to speak or transmit tones identifying departments available for customer service. For example, the voice prompt message may inform the calling customer to speak or transmit a numerical 1 command to be connected with an order department. The voice prompt message continues to inform the calling customer that a spoken or transmitted numerical 2, 3, 4 or 5 command operates to connect the customer with billing, appliance, apparel or customer information departments, respectively. After receiving the voice prompt message, the calling customer speaks or transmits a numerical number command identifying a department which the calling customer has selected.
Voice response units transmit the entire voice prompt message to the calling customer then waits to receive a customer response. Experienced customers often do not wait until the end of the voice prompt message but speak or transmit a command while receiving the voice prompt message. Many types of customer telephone lines may be connected with a voice response unit. For example, some customer lines may have short 2-wire telephone lines while others may have long repeated 2-wire or 4-wire toll telephone lines. A problem arises in that impedance mismatches arising from the connection of various types of customer telephone lines with a voice response unit reflect a part of the voice prompt message transmitted to the calling customer back to the voice response unit. The reflected part of the voice prompt message is combined with a customer command transmitted during the voice prompt message. The combined customer command and reflected voice prompt message results in a garbled message returned to the voice response unit. Such garbled messages are not recognized by the voice response unit. The calling customer must wait until the end of the transmitted voice prompt message to transmit a responsive command.